This just might be one of the worst-kept secrets in New York City politics.

A new website has been set up by Brooklyn Borough President Eric Adams with the simple message, “Imagine what he will embark upon in 2021.”

No where on the new site does it mention that Adams has his sights set on the city's top job, but it's been well known since around 2015 that Adams would love to become the second black mayor in the history of New York City.

And yet, his fundraising site continues to try and play coy. The site mentions his past accomplishments, including his experience as a police captain and state senator, but never explicitly details his ambitions for the mayoral post, only promising “Eric is ready to service this city that he loves in a major way.”

But apparently his backers didn't get the message, as many have reached out to political donors asking for their help in supporting “his efforts to become the second black mayor of this great city!”

But just to be clear, Adams is not necessarily running for mayor, although he has registered a campaign committee for 2021 with the state, like any self-respecting mayoral candidate would do.

But he's not running for mayor, just something big in 2021. Got that?

This might be crowded race on the Democratic side, if early predictions on potential candidates can be trusted. Insiders' lists include Comptroller Scott Stringer, Public Advocate Letitia James, Bronx Borough President Ruben Diaz and Congressman Hakeem Jeffries in addition to Adams.

With three candidates with strong Brooklyn ties in Adams, James and Jeffries, the Kings County Democratic Party might have a tough choice to make in a few years.